source
The type of source database. The default value is MySQL. For the correspondence between supported source libraries and target libraries, see Supported Databases. When the database type of the source instance is MONGODB, you also need to pass in some information in the reserved parameter Reserve, for the configuration method, see the description of Reserve parameters. Valid values: AS400, DB2, DMSPOLARDB, HBASE, MONGODB, MSSQL, MySQL, ORACLE, PolarDB, POLARDBX20, POLARDB_O, POSTGRESQL, TERADATA.